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  1. Shahriar

    Help me download this Plasma Training manual

    Hi One of my friend has uploaded a Plasma TV training document for me to a free site. But unfortunately the damn proxy-serverds do not let me download it. I will apprecaite it If anyboady could download it and Upload it some where or email it to me. It will expire within 6 days. here the...
  2. Shahriar

    Plasma TV training document

    Dear jomiservice ThanK you very much for your articles. they are very useful for me. shahriar
  3. Shahriar

    Plasma TV training document

    Hi I want to know if anybody has any Plasma circuit description document or any Plasma training document. or any link to download. There are lots of service manuals on th web but as U know there isn't any circuit description in service manuals. ThanX Shahriar
  4. Shahriar

    Image processing in Robot

    Dear $@$ sometime ago I decided to build a line follower robot by a small camera.( Not a Web cam.) I had decided to detect between the black Line and the white background by proceesind the video sinal. and to position it by other pulses in a component video signal. U should have enough...
  5. Shahriar

    Choosing PA for my 3-way active Cross over circuit

    Hi I want to build this Active 3-way cross-over circuit. But I do Not kow how to choose Power amplifiers. Here the problems: 1- If I choose a 15W subwoofer and a 15W STK power Amplier (STK4121) for it then what kind of Midrange and tweeter will be needed? Does it mean I have to choose a 15w...
  6. Shahriar

    Pc Resets after a while. Where to look for the Probelm?

    Dear mvs sarma Thank you very much i will check it out. BTW, don't you have any Idea about Over Voltage protection? Dear Ante. You are right, maybe many of them don't worth to repair, but many of them has just a bad diode bridge or a blow up cap. and repairing of them takes about 20 minutes. ...
  7. Shahriar

    How this regulator works?

    Hi, ThanX both of you, I Understood it now.  ;D But what is the roll of L6 there? Shahriar
  8. Shahriar

    Pc Resets after a while. Where to look for the Probelm?

    Hi I am trying to repair Some ATX power Supplies.but some of them do not have ordinary faults. Most of them are in these two categories. 1- The computer assembler told me that with this bad PS, computer is working well but after a while (i.e. 10 Minutes or more) it will resets. but when they...
  9. Shahriar

    How this regulator works?

    Hi Look at the this OLD ATX power supply. Can somebody explain how the 3.3V regulatosr built around TL431 IC works. It looks like a Shunt regulator but very strange. I know How TL431 works but can't understand this circuit. i.e. if Q13 Current changes, how does this affect 3.3V rail. (look at...
  10. Shahriar

    85C Cap ESR vs 105C Cap ESR!

    Look what another guy has said about this topic: ESR is usually something to be minimized in a capacitor. However, where the original design depended (probably by accident) on a certain ESR, this may not always be the case: (From: Lee Dunbar ([email protected]).) Substitutions of low ESR caps...
  11. Shahriar

    85C Cap ESR vs 105C Cap ESR!

    Hi I can remind some times ago some one has written that it is better to replace 85'C Caps with 105C caps in old devices. (I think it was audioguru) Today, I was reading an article about SMPS troubleshooting. Look what a repair man has said: "(From: Jeroen H. Stessen...
  12. Shahriar

    50Hz when you touch Oscilloscope probe

    Dear Audioguru A TV tuner is designed to receive a voltage around 400uV Upto 600uV From antenna. then how our body can produce a 6V signal. I think there are some other reasons in addition to electromagnetic in creating such big signal. shahriar
  13. Shahriar

    50Hz when you touch Oscilloscope probe

    Dear Audioguru 1- I Connect the Probe to an Antenna and a 50Hz signal appeared with pick voltage about 2V. 2- when I touched the antenna while it was connected to Probe a 2.2V 50Hz signal appeared. 3- when I touched the probe a 50Hz, 6V signal appeared 4- when I touched the probe a 50Hz, 5.7V...
  14. Shahriar

    50Hz when you touch Oscilloscope probe

    why when you touch Oscilloscope probe a 50Hz signal will appear? I think it should be related somehow to  Earth connecttion. ThanX Shahriar
  15. Shahriar

    Creating/making Music ICs

    Just tak a look at Datasheet, You will find what you need there. A mic is not always needed. Shahriar
  16. Shahriar

    Creating/making Music ICs

    Look for ISD25XX Series. i.e. ISD2560 with 60second storage or ISD25120 with 120s. They have all things you need. i.e. Amplifer, Address Pins, ... You just connect a Mic. BTW, as I understood, the storage for all Ics are the same, the difference between 120s with 60s is in ADC Sample rate. In...
  17. Shahriar

    What si that series resistor with Diode in and Inductor Switch circuit?

    Tell me if I got it. ;) The resistor will Dissipate power to remove the stored energy in Inductor. without Resistor it takes longer. I think for relays, because The resistance is high enough, they don't put this resistor but for an inductor which its Resistance is low, they put such Resistor...
  18. Shahriar

    What si that series resistor with Diode in and Inductor Switch circuit?

    Hi When an inductor is to be switched by a transistor, Usually a Diode is placed in parrarell with inductor to Protect Transitor from High voltage created with Inductor when Switch turns off. (I have forgotten the English name of this diode) But sth. a Resistor is placed in series with this...
  19. Shahriar

    Timer

    Here another Useful link for IC 4510 - I think this is all you need. http://www.doctronics.co.uk/4510.htm Shahriar
  20. Shahriar

    Timer

    ِDear Herman For Counting down the UP/Down pin should taken low. if you want when counting is finished, the counter resets, you should connect the Max/Min output to Load Input via a NOT gate or a NPN transistor While all Outputs are pulled down via Appropriate Resistors (If IC doesn't have...
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